Both were very easy to use once you had the hang of the ticket machines.
To buy a ticket, there are machines on the platforms in most of the stations. You have to pick where you are going & then put your money in. The problem comes when the station you want is not on the list!! So the best thing to do is pick the nearest one & pay that much. There were no instructions on what to do otherwise & it worked ok for us.
Maps are available from the tourist offices & there is a good one in the Hauptbahnhof.
The other good thing is that all the underground trains have a schedule on the platforms so if you are planning an onward journey it is really easy.
There are also street trains but we didn't have time to try these.

